Workers should be given places to rest at work to help boost productivity, according to new official guidance.

Downtime at work can help employees switch off and get better quality sleep at night, Public Health England says.

Better sleep maintains cognitive function in employees, as well as cutting health risks, a blog post from the health body says.

Companies should encourage better "sleep hygiene", it adds.

"Sleep is not just critical to recovery, it essential for maintaining cognitive skills such as communicating well, remembering key information and being creative and flexible in thought," says Justin Varney, national lead for adult health and wellbeing at Public Health England, in the blog post.

GDP hit

Sleep loss costs the UK economy billions of pounds per year, according to research by Rand Corporation.

Lower productivity comes through "absenteeism, when people don't show up to work; and presenteeism, when people show up but are working at suboptimal levels", according to Rand researcher Marco Hafner.

People who fail to sleep between seven and nine hours a day find their performance at work deteriorates, are easily distracted, have a less effective memory and are more likely to be in a bad mood, Mr Varney writes.

There are also links between lack of proper sleep and high blood pressure, heart disease and diabetes, he adds.

The guidance, which was developed with corporate responsibility organisation Business in the Community, recommends that employers help their employees be open about any sleep-related issues they have.

Among steps employers can take is devising shift patterns that give workers time to recover between shifts, and letting workers "unplug" by reducing or stopping out-of-work emails.

People can also take their own steps to improve sleep, including:

*Fixed bedtimes

*Regular exercise

*Avoiding caffeine, nicotine and alcohol late at night

*Not watching TV in bed

*Avoiding blue light from screens before and during sleep

Some firms already encourage employees to have downtime at work. London-based money transfer service firm TransferWise has a hammock and sauna on its premises, for example.

And accountancy company PwC, as part of a training programme on resilience, tries to help its staff improve the quality of their sleep